Photo: Larry D. Moore · CC BY 4.0Jerome’s winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 90°, a January night drops to 21°, and about 24 inches of snow falls in a normal winter.
A year in Jerome at a glance
Each month’s typical high and low, and what it brings.
What stands out about Jerome’s climate
Compared with towns across the U.S., with Jerome’s place in Idaho beside it.
What a year in Jerome feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 166 frost-free days a year
In half of years the last 32° night comes by May 2 and the first by October 14. Frost and day counts come from NOAA’s station at Jerome, ID, 1.1 miles from the town’s center, at about the same height.
The 2023 USDA map puts Jerome’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −1°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 24 inches of snow a winter
Snow, measured at Twin Falls 6 E, ID, falls mostly in January. Precipitation (rain plus melted snow) adds up to 10 inches a year; December is the wettest month and July the driest. Rain or snow falls on about 86 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Jerome
89% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Jerome, ID.
Living with Jerome’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
166 frost-free days in zone 6b. The last frost comes by May 2 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 14.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 0.2 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Jerome from natural hazards, river flooding is the largest share (43%); heat waves, cold waves, winter storms and ice storms together are 43%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Jerome and similar climates
TownRatings has no climate map of the towns around Jerome yet.
Climates most like Jerome’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Jerome, ID | 21° | 90° | 10" | 24" |
| Gardnerville Ranchos, NV | 23° | 90° | 11" | 22" |
| Eagle Mountain, UT | 18° | 91° | 10" | 26" |
| Terrace Heights, WA | 25° | 89° | 9" | 20" |
| White Rock, NM | 18° | 89° | 13" | 20" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Jerome averaged 1.5° warmer than the 1900s. The biggest change is in January (+3.1°).
A bigger shift than in 58% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Jerome compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Jerome’s place among Idaho’s.
Jerome weather by month
Highs, lows and precipitation from NOAA’s grid at Jerome’s center; snow, wet days and snow on the ground from Twin Falls 6 E, ID. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 37° | 21° | 1.2" | 7.8" | 11 | 20° – 37° |
| February | 43° | 24° | 0.8" | 5.5" | 9 | 25° – 42° |
| March | 53° | 31° | 1.0" | 1.9" | 9 | 36° – 47° |
| April | 61° | 35° | 1.0" | 0.5" | 10 | 43° – 53° |
| May | 71° | 43° | 1.2" | 0.0" | 9 | 50° – 63° |
| June | 80° | 50° | 0.6" | 0.0" | 7 | 59° – 72° |
| July | 90° | 57° | 0.1" | 0.0" | 3 | 63° – 79° |
| August | 88° | 55° | 0.2" | 0.0" | 3 | 66° – 75° |
| September | 78° | 46° | 0.4" | 0.0" | 3 | 58° – 66° |
| October | 64° | 36° | 0.8" | 0.5" | 5 | 43° – 57° |
| November | 48° | 28° | 1.0" | 2.0" | 8 | 30° – 44° |
| December | 37° | 21° | 1.5" | 6.0" | 10 | 24° – 35° |
| Year | 62° | 37° | 9.8" | 24.2" | 86 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 25° to 42°. September is the most reliable, staying within 8°.
Where Jerome’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Jerome’s center.
- Snow: Twin Falls 6 E, ID.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Jerome, ID, 1.1 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Jerome’s climate
What is the weather like in Jerome?
A typical July afternoon reaches 90°, a January night drops to 21°, and about 24 inches of snow falls in a normal winter. Colder January nights than 52% of U.S. towns; hotter July afternoons than 78% of U.S. towns.
How cold does it get in Jerome in winter?
December nights average 21°. About 153 nights a year reach 32° or below and 2 reach 0° or below. In the coldest December of the last 30 years the month averaged 24°.
How much snow does Jerome get?
About 24 inches in a normal winter at Twin Falls 6 E, ID, most of it in January.
How hot does it get in Jerome?
July, with a typical high of 90° and a low of 57°. About 54 days a year reach 90° and 8 reach 100° (Jerome, ID).
When is the first and last frost in Jerome?
In half of years the last spring frost (32°) comes by May 2 and the first fall frost by October 14, about 166 frost-free days, at Jerome, ID.
What growing zone is Jerome in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −1°.
What is the best time of year to visit Jerome?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Jerome getting warmer?
Yes: 1991–2020 averaged 1.5° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 58% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Jerome.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.